v911 throttle curve question

Hey guys, I debated what sub-forum to put this question in and ended up here, dont know if it's best but dont really know what my question fits...



I have been using (and modifying to taste) a v911 config file I found here, I'm very sorry but I do not recall who originally made / shared it to give credit to. Again I'm not at all claiming it's mine, all I've done is make some changes to fit my needs, the setup work initially goes to whoever it rightfully belongs to (a member here). Even with the mods I'm making it's a hell of a starting place and I'm more than thankful to have found it (and all the other files I've used from here).


I have been looking for how to adjust the throttle curve but only found detailed instructions for FBL mixing, infact one tutorial starts out by claiming 4-ch fly bar FP mixing is the hardest to do!

The problem I'm trying to correct is that I dont have a very good throttle response on the low end, from -100 to -88 or -87 it's dead, then all the sudden it spins up (fast enough to torque around some), same when throttling down (not that it's as important, but still annoying that it's not correct). On throttle up it's so noticeable it's more like applying 10-15% throttle with the hold switch off then flipping it on vs. starting at 0% and slowly increasing.

That's the most noticeable time I can describe but overall I feel like my particular heli could benefit from a different curve in general, not that the curve in the file is bad in any way, just that it doesnt fit my particular model (and it's mods) and my flying style.

Your current curve is just a 1-1 map.

Change it to N-Point (Based on your 88% figure, I'd say 9). Now set the points at 25% apart: 1 is -100%, 2 is -75%, 3 is -50%, ... 8 is 75%, 9 is 100%. That duplicates your current 1-1 mix.

Now you can adjust the points to taste. For instance, bump point 2 up to 50%, and then the following points to get a straight line from point 2 to point 9. That will make the first 12% of the throttle curve be twice as sensitive as it is in the 1-1 curve, and slow the rest down a bit to compensate.

If you can fell the slope transition at point 2, setting Smooth on will help some. If you find you want finer control, you can try an 11 or 13 point curve.

OK this is what I did, it flies (as you stated) the same so I just want to make sure I set it up right before I start trying to tune it...

[mixer]
src=THR
dest=Ch3
curvetype=9-points
points=-100,-75, -50, -25,0, 25, 50, 75, 100


edit: I'm trying to set this up in code, is that the best idea or is there a better way [in the Tx's GUI]?

If you're going to edit the file directly, it should be "curvetype=9point". But I'd use the GUI in the TX - you can see what the curve looks like there. Maybe start with that one, since setting them up originally is a bit of a pain.

This is where I'm at now, I've tried both the method you told me for making it more sensitive down low as well as going the other way, no matter what changes I make it's always the same, nothing till exactly -87 then it spools up all the sudden. At -88 it's dead, at -87 it's alive.


[mixer]
src=THR
dest=Ch3
curvetype=11point
points=-100,-50,-27,-9,10,32,46,64,77,89,100
smooth=1

note I've tried both with and without "smooth"

Just a wild guess, but try making that first point -88 instead of -100. If that works, you can probably go back to a 1-1 curve with an offset of 12 and a scale to bring the max back to 100.

Have you tried a wltoys Tx? This may be an issue with your V911.

I have not, I no longer have a working one. I do however have 3 V911's, one (my main) a V911-pro, the other 2 regular (but "new" versions) and they all 3 react identical. I killed my only remaining factory Tx making it into a toy for my 3 year old son (using the sticks to control RGB LED's placed all around it) after harvesting the module out of it.

Will report back about setting it to start at -88

Great idea man, that did it! Funny thing is, before it would start spinning at -87, at -88 it would sit there still. When I switched the bottom point to -88 it would start spinning the moment I flipped the hold switch up. Ended up setting it to -90 and I like how it's working now.


Could you explain how to set the offset and scale to go back to a 1 to 1 curve? I dont understand that.

Thanks again man, its 100% better now!

Well, you could probably just set the offset to 10. That would make the 1-1 curve run from -90 to 110. Might make the top end quit responding, but it might just translate to a little extra lift.

If you want the top to be 100, then your range is 190 instead of 200, so the scale is 95, and your range is -95 to 95. Then set the offset to 5, making the range -90 to 100.